The present invention relates to the information display arts and, more particularly, to a novel method and apparatus for volumetric projection rendering from any angle of viewable three-dimensional (3D) data.
In the medical imaging arts, it is well known to construct synthetic X-ray-like images of the interior of a sample volume (e.g. a portion of a patient) by projecting 3D data into a series of views at different angles. A cine loop of rotating projections can be viewed to enhance the perception of depth. In some cases, improved visualization can be accomplished by segmentation of the viewable volume using a model of opaqueness. However, surface rendering, utilizing methods such as those described and claimed in U.S. Pat. Nos. 4,710,876 and 4,719,585, merely creates a shaded image resembling a photograph of the object. A volumetrically-rendered image is often preferable to a surface model, for providing images of a volume-of-interest in which vessel morphology can be viewed with detail from a magnetic resonance (MR) examination, comparable to X-ray techniques. It is desirable to provide a maximum pixel projective display, wherein the maximum intensity of each pixel along the line-of-sight is presented, as such projective display is in a form more natural than the surface display, to the angiographer. Unfortunately, the volumetric display requires more processing and has hitherto been too slow for clinical use in a MR scanner apparatus. It is therefore highly desirable to provide a method, and companion apparatus, for providing a rapidly-processible volumetric medical imaging display.